Having shot hundreds of head of big game. Then having seen hundreds of heads of big game shot by others.
With calibers from 22LF to 460 Weatherby.
Having used the 30-06 on game for over 5 decades
With many dozen of different bullet designs. It is possible for bullet from a high powered rifle not to exit the body.
Bullet design is critical how it preforms shot angle muzzle velocity impact velocity all play a role.
Once it leaves the muzzle different factors all play a role in what happens when it hits a target.
For awhile I used a 125gr Serria at 3200fps out of one of my 30-06’s.
It would enter leaving a 308dia. hole mush every thing inside and not exit.
Killed fast but without a exit hole blood trails were iffy.
I decided a tougher heaver bullet was better.
So without knowing a lot of specifics saying a bullet from a 30-06. Well always leave a exit wound or hole.
Is wrong.
If you really think that a high powered rifle slug will be stopped in its track by a puny human neck then you are insane. Totally, completely insane. I gave the example of what it does by reminding what we all saw what it did to JFK’s skull.